Locking device for electric lamps, &amp;c.



A. D. BARTLETT.

LOOKING DEVIGB FOR ELECTRIC LAMPS, 6:6.

APPLICATION FILED JUNE 9, 1913.

1,092,627. Patented Apr. 7, 191

Z5 .6 awuemtoz {7/ I K W ALBERT D. BARTLETT, OF WASHINGTON, DISTRICT OFCOLUMBIA.

LOCKING DEVICE FOR ELECTRIC LAMPS, &c.

Specification of Letters Patent.

Patented Apr. 7, 1914? Application filed June 9, 1913. Serial No.772,724.

To all whom it may concern Be it known that I, ALBERT D. BARTLETT, acitizen of the United States, residing at Washington, in the District ofColumbia,

'have invented new and useful )Improvements in Looking Devices forElectric Lamps, 0., of which the following is a specification.

This invention relates to an improved locking device for electric lamps,separable connectors, and the like.

It is a common experience in large establishments, where numerousincandescent lamps are used, and to which dishonest and irresponsiblepeople have access, to have the lamps removed from their sockets byunauthorized persons, resulting in a pecuniary loss of considerablemagnitude. It is also not unusual to have the parts of detachableconnectors of various other types removed or tampered with, likewiseresulting in loss of the parts and derangement of the elec tric system,inflicting further damage upon the owners or operators of theinstallation.

One of the objects of the present invention is to provide simple meansfor normally preventing the separation of a lamp, or other removableconnector, from its socket, except by authorized persons.

A further object is to provide means of this character which areelectrically controlled.

A further object is to provide means which are also selectivelycontrolled, whereby the means which will permitremoval of the lamps, orthe like of one installation, will not operate in connection with thoseof another installation.

The invention will be hereinafter fully set forth and particularlypointed out in the claims.

In the accompanying drawing:Figures 1 and 2 are side views taken atright angles to each other. illustrating a lamp socketwith myinventionappliedthereto, the easing being shown in section. Fig. 3 is a top planview of the socket. Fig. 4 is a top plan view of the screw shell removedfrom the socket. Fig. 5 is a longitudinal sectional view on the line 55,Fig.3. Fig. 6 is a similar view on the line 6-6, Fig. 3. Fig. 7 is aview illustrating the resistance key. Fig. 8 is a detail illustrating aslight modification. Fig. 9 is an enlarged detail view illustrating thesolenoid.

Referring to the drawing, 10 designates a porcelain lamp socket whichmay be of any suitable or preferred type,t-he form illustrated beingarbitrarily selected for illustrative purposes only. Said socket, asillustrated, is provided with a central chamber 11 in which is locatedthe bearing member-12 in which is rotat-ablv mounted the. key shaft 13provided with the usual key 14. Said bearing member is held in positionby means of a screw 15 extending through a suitable bore 16 centrallylocated with respect to said block. Said bearing member 12 is alsoprovided with an car 17 to which the terminal of one of the electricconductors or line wires 18 is connected in the usual manner. Theporcelain block 10 is also provided with a second chamber 18 whichintersects the chamber 11, and in which is located the bearing member 20to which the screw shell 21 is swiveled by means of the rivet or pin 22,the latter also serving as the usual central contact for the lamp 23.The swivelbearing member 20 is secured in position by means of screws 24extending through the block 10, and the same is provided with anupstanding lug 25 to which the end of the other conductor or line wire26 is secured. in the usual manner. In the operation of the lamp, thecircuit is closed by the key 14. one end of which contacts with the endwall of the shell 21. and the other end with a spring arm 27 secured tothe bearing member 12. The construction above described is well knownand I do not care to limit myself to its use.

Tn carrying out my invention I provide the block 10 with a bore near theperinhcrv thereof. and locate in said bore a small solnoid coil 30. thelower end of which is provided with a flange 31 which abuts against acomplemental shoulder formed in the bore. One terminal of said solenoidis connected with the screw 15. bv a wire 39 thereby placing thesolenoid in circuitwith the line wire 18. The other terminal of thesolenoid is connected with a contact 33 embedded in the circular surfaceof the block 10. second contact 34 is similarlv embedded in the block 10adiacent contact and is connected bv a-suitable wire 35 with one of thescrews 94, whereby said contact 34 is placed in circuit with the linewire 26. The core 36 of the solenoid constitutes the locking member. andcomprises a rod of magnetic material having a head at one end againstwhich bears a retracting spring 37 which acts against a suitableabutment. The other end of said rod is provided with a short length ofnonmagnetic material which is designed to enter complemental openings 38in the end wall of shell 21 to prevent rotation of the latter on theswivel pin 22. In operation the spring normally holds the core 36 retracted so that the shell 22 may freely turn on its swivel. When thecircuit is closed across contacts 33 and 34 the solenoid coil isenergized, moving the core against the action of the spring 37, causingthe nonmagnetic end of the core to enter one of the openings 38, therebylocking the shell 21 against rotation. IVhile thus locked the lamp maybe screwed into the shell or removed, as the case may be. As soon as thecircuit is broken at the contacts 33, 34, the core 36 is againretracted, permitting the shell 21 to turn on its swivel, therebyfrustrating any attempt to remove the lamp as the screw shell will turntherewith. The casing of the lamp socket covers'the shell 21 and therebyprevents access to the shell in any manner.

The circuit may be closed at the contacts 33, 34 in any suitable manner.I prefer, however, to employ a resistance key such as illustrated inFig. 7. Said resistance key comprises a casing 40 in which is located aresistance coil 41 having terminals 42 which may be placed in engagementwith contacts 33 and 34. The end of casing 40 from which the terminals42 project, is preferably concaved, as indicated at 43, so as to form aseat for the convexed wall of the socket casing surrounding the block10, thereby preventing wabbling of the key when it is desired to operatethe solenoid.

The contacts 33, 34, may, if desired, be arranged flush with the surfaceof the block 10 as illustrated in Fig. 6, the socket casing beingprovided with insulated openings 44 through which the terminals 42 ofthe resistance key may project. Or, said block 10 may be provided withteats or protuberances 45 through which the contacts 33, 34, extend, thesocket casing being slotted to permit the parts to be assembled. It isobvious that the windings of the solenoid 30 and those of the resistancekey may be so rela tively varied that the solenoid will only respond toa circuit closed though a resistance key having a predetermined winding.In this manner each installation will be provided with a'key which willnot operate in conjunction with any other installation, and saidinstallation will not respond to any other key.

In order to prevent the inclosing casing surrounding shell 21 from beingsqueezed in 'sufiiciently to prevent rotation of said shell,

I provide a suitable reinforcement for said casing. .For instance, inthe drawings I have shown said casing as provided with an offset annularportion 46 in which is secured a steel reinforcing band 47 of sufficientstrength to resist any pressure tending to squeeze the casing againstthe shell for the purpose of preventing rotation of the latter. In thismanner I guard against removal of the separable member except by onepossessing-the proper resistance key.

Having thus explained the nature of my invention and described anoperative man ner of constructing and using the same, although withoutattempting to set forth all of the forms in which it maybe made, or allof the forms of its use,-what I claim 1s 1. In a locking device forelectric lamps, an insulating block, and an electric locking devicecarried thereby comprising a bolt, a spring coil for holding said boltnormally retracted, and a magnetic coil for projecting said bolt inopposition to said spring, in combination with a screw shell having oneend wall swiveled to one end of said insu lating block, the end wall ofsaid shell being provided with complemental means to be engaged by saidbolt.

2. In a locking device for electric lamps, an insulating block, and anelectric locking device embedded therein and comprising a reciprocablebolt, a spring coil for holding said bolt normally retracted, and amagnetic coil for projecting said boltv in opposition to said spring, incombination with a shell having one end wall swiveled to one end of saidinsulating block, the end wall of said shell being provided withcomplemental means spaced from the periphery thereof to be engaged bysaid bolt.

3. In a locking device for electric lamps, an insulating block, and anelectrically operated bolt carried by said insulating block, incombination with a screw shell having one end swiveled to oneend of saidinsulating block, the end wall of said shell being provided Withcomplement-a1 means to be engaged by said bolt.

4. In a locking device for electric lamps, an insulating block, and anelectric locking device carried thereby comprising a bolt, a spring coilfor holding said bolt normally retracted, and a magnetic coil forprojecting said bolt in opposition to said spring, in combination with ascrew shell having one end wall swiveled to one end of said insulatingblock, the end wall of said shell being provided with complemental meansto be engaged by said bolt, and means independent of' the lamp forcontrolling the circuit to said coil,

5. A locking device of the character described comprising an insulatingblock, a shell swiveled thereto, and electrically operated means ,forpreventing relative rotation of said block and shell, in combinationwith an electrical memberindependent of said lamp for controlling thecircuit to said electrically operated 'means.

6. A locking device of the character described comprising an insulatingblock, a shell swiveled thereto, a solenoid located Within said blockand provided with a core arranged to engage said shell, in combinationwith an electrical member independent of said lamp for controlling saidsolenoid.

7.. In a locking device for electric lamps, an insulating block, lampcontacts therein, line wires leading to said contacts, and an electriclocking device .carried by said block and electrically connected withsaid line wires in combination with a screw shell hav ing one end wallswiveled to one end of said insulating block, the end wall of said shellbeing provided with complemental means to be engaged by said lockingdevice.

8. In a locking device for electric lamps, an insulating block, lampcontacts therein, line wires leading to said contacts, a solenoid coilcarried by said socket and connected with said line wires, and a boltforming the core of said solenoid, in combination with a screw shellhaving one end wall swiveled to one end of said insulating block, theend wall of said shell being provided with complemental means to beengaged by said bolt.

-9. A locking device of the character described comprising an insulatingblock,' a shell swiveled thereto, electrically operated means forpreventing relative rotation of said block and shell, and means normallydetached from said block and said shell for closing the circuit to saidelectrically operated means.

10. A locking device of the character described comprising an insulatingblock provided with contacts, line Wires leading to said contacts, ashell swiveled to said block, electrically operated means for preventingrelative rotation of said block and shell, and means normally detachedfrom said block and said shell for closing the circuit from said linewires to said electrically operated means.

11. The combination with a key socket, and line wires leading thereinto,and a screw shell having one end swiveled to one end of said socket, ofa bolt for preventing relative rotation of said key socket and saidshell, means for holding said bolt normally retracted, and electricalmeans in circuit with said line wires for moving said bolt in oppositionto its retracting means.

12. The combination with a key socket and a screw shell swiveledthereto, of a locl 3- ing member for preventing relative rotation ofsaid socket and shell, a casing inclosing said parts, and a reinforcingring engaging the inner wall of said casing and surrounding said shcllto prevent crushing of the latter.

In testimony whereof I have hereunto set my hand in the presence of twosubscribing witnesses,

ALBERT D. BARTLETT.

In presence of- \VM. S. Honors, VVAL'rnn P. PLUMLEY.

(Jopies of this patent may be obtained for five cents each, byaddressing the (lemmissioner of ?atcnts, Washington, D. G.

